Sequentially deployed transcatheter mitral valve prosthesis

ABSTRACT

A sequentially deployed prosthetic cardiac valve includes a self-expanding frame having an atrial skirt, a ventricular skirt, and an annular region disposed therebetween. A first anterior tab is disposed on an anterior portion of the frame. A posterior tab is on a posterior portion of the self-expanding frame. The frame may be designed so that any portion may expand sequentially in any desired order. For example, a portion of the first anterior tab and a portion of the posterior tab may partially self-expand first. Next, the first anterior tab may fully self-expand before the posterior tab fully self-expands. The posterior tab may fully self-expand next followed by the ventricular skirt, or the ventricular skirt may self-expand next followed by full expansion of the posterior tab.

CROSS-REFERENCE

The present application is a continuation of U.S. patent applicationSer. No. 13/679,920 filed Nov. 16, 2012, now U.S. Pat. No. 9,308,087,which is a non-provisional of, and claims the benefit of U.S.Provisional Patent Application No. 61/563,156 filed Nov. 23, 2011; theentire contents of which are incorporated herein by reference.

The present application is related to U.S. patent application Ser. No.13/096,572 filed Apr. 28, 2011, now U.S. Pat. No. 8,579,964, the entirecontents of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally relates to medical devices and methods,and more particularly relates to the treatment of valve insufficiency,such as mitral insufficiency, also referred to as mitral regurgitation.The use of prosthetic valves delivered by traditional surgicalimplantation methods, or by a less invasive percutaneous catheter or byminimally invasive transapical methods are one possible treatment forvalvar insufficiency (also referred to as regurgitation).

The heart of vertebrate animals is divided into four chambers, and isequipped with four valves (the mitral, aortic, pulmonary and tricuspidvalves) that ensure that blood pumped by the heart flows in a forwarddirection through the cardiovascular system. The mitral valve of ahealthy heart prevents the backflow of blood from the left ventricleinto the left atrium of the heart, and comprises two flexible leaflets(anterior and posterior) that close when the left ventricle contracts.The leaflets are attached to a fibrous annulus, and their free edges aretethered by subvalvular chordae tendineae to papillary muscles in theleft ventricle to prevent them from prolapsing into the left atriumduring the contraction of the left ventricle.

Various cardiac diseases or degenerative changes may cause dysfunctionin any of these portions of the mitral valve apparatus, causing themitral valve to become abnormally narrowed or dilated, or to allow bloodto leak (i.e. regurgitate) from the left ventricle back into the leftatrium. Any such impairments compromise cardiac sufficiency, and can bedebilitating or life threatening.

Numerous surgical methods and devices have accordingly been developed totreat mitral valve dysfunction, including open-heart surgical techniquesfor replacing, repairing or re-shaping the native mitral valveapparatus, and the surgical implantation of various prosthetic devicessuch as annuloplasty rings to modify the anatomy of the native mitralvalve. More recently, less invasive transcatheter techniques for thedelivery of replacement mitral valve assemblies have been developed. Insuch techniques, a prosthetic valve is generally mounted in a crimpedstate on the end of a flexible catheter and advanced through a bloodvessel or the body of the patient until the valve reaches theimplantation site. The prosthetic valve is then expanded to itsfunctional size at the site of the defective native valve.

While these devices and methods are promising treatments for valvarinsufficiency, they can be difficult to deliver, expensive tomanufacture, or may not be indicated for all patients. Therefore, itwould be desirable to provide improved devices and methods for thetreatment of valvar insufficiency such as mitral insufficiency. At leastsome of these objectives will be met by the devices and methodsdisclosed below.

2. Description of the Background Art

By way of example, PCT international patent number PCT/US2008/054410(published as PCT international publication no. WO2008/103722), thedisclosure of which is hereby incorporated by reference, describes atranscatheter mitral valve prosthesis that comprises a resilient ring, aplurality of leaflet membranes mounted with respect to the ring so as topermit blood flow therethrough in one direction, and a plurality oftissue-engaging positioning elements movably mounted with respect to thering and dimensioned to grip the anatomical structure of the heart valveannulus, heart valve leaflets, and/or heart wall. Each of thepositioning elements defines respective proximal, intermediate, anddistal tissue engaging regions cooperatively configured and dimensionedto simultaneously engage separate corresponding areas of the tissue ofan anatomical structure, and may include respective first, second, andthird elongate tissue-piercing elements. The valve prosthesis may alsoinclude a skirt mounted with respect to the resilient ring for sealing aperiphery of the valve prosthesis against a reverse flow of blood aroundthe valve prosthesis.

PCT international patent number PCT/US2009/041754 (published as PCTinternational publication no. WO2009/134701), the disclosure of which ishereby incorporated by reference, describes a prosthetic mitral valveassembly that comprises an anchor or outer support frame with a flaredupper end and a tapered portion to fit the contours of the native mitralvalve, and a tissue-based one-way valve mounted therein. The assembly isadapted to expand radially outwardly and into contact with the nativeheart tissue to create a pressure fit, and further includes tensionmembers anchoring the leaflets of the valve assembly to a suitablelocation on the heart to function as prosthetic chordae tendineae.

Also known are prosthetic mitral valve assemblies that utilize a clawstructure for attachment of the prosthesis to the heart (see, forexample, U.S. patent publication no. US2007/0016286 to Hermann et al.,the disclosure of which is hereby incorporated by reference), as areprosthetic mitral valve assemblies that rely on the application of axialrather than radial clamping forces to facilitate the self-positioningand self-anchoring of the prosthesis with respect to the nativeanatomical structure.

Another method which has been proposed as a treatment of mitral valveregurgitation is the surgical bow tie method, which recently has beenadapted into a minimally invasive catheter based treatment where animplant is used to clip the valve leaflets together. This procedure ismore fully disclosed in the scientific and patent literature, such as inU.S. Pat. No. 6,629,534 to St. Goar et al., the entire contents of whichare incorporated herein by reference.

Other relevant publications include U.S. patent publication no.2011/0015731 to Carpentier et al. and WO2011/137531 to Lane et al. Whilesome of these devices and methods are promising, there still is a needfor improved devices and methods that will further allow more accuratepositioning of a prosthetic valve and that will also more securelyanchor the valve in place. At least some of these objectives will be metby the exemplary embodiments disclosed herein.

SUMMARY OF THE INVENTION

The present invention generally relates to medical devices and methods,and more particularly prosthetic valves used to treat mitralregurgitation. While the present disclosure focuses on the use of aprosthetic valve for treating mitral regurgitation, this is not intendedto be limiting. The prosthetic valves disclosed herein may also be usedto treat other body valves including other heart valves or venousvalves. Exemplary heart valves include the aortic valve, the tricuspidvalve, or the pulmonary valve.

In a first aspect of the present invention, a method of delivering animplantable prosthetic valve to a patient's heart which has a mitralvalve with an anterior leaflet and a posterior leaflet, comprisesproviding a prosthetic valve, wherein the prosthetic valve comprises anexpandable frame having a first end, a second end opposite the firstend, a first anterior tab on an anterior portion of the expandableframe, a posterior tab on a posterior portion of the expandable frame,and a ventricular skirt adjacent the first end of the expandable frame.The prosthetic valve has an expanded configuration for engaging theheart and a collapsed configuration. The prosthetic valve is deliveredin the collapsed configuration to the patient's heart adjacent themitral valve, and the first anterior tab is expanded radially outwardsuch that a tip portion of the first anterior tab engages a firstfibrous trigone on a first side of the anterior leaflet of the mitralvalve. The anterior chordae tendineae adjacent the anterior leaflet aredisposed between the first anterior tab and an outer anterior surface ofthe ventricular skirt. After radially expanding the first anterior tab,the posterior tab is radially expanded outward such that the posteriorleaflet of the mitral valve and adjacent posterior chordae tendinae aredisposed between the posterior tab and an outer posterior surface of theventricular skirt. After radially expanding the posterior tab, theventricular skirt is radially expanded outward thereby engaging theanterior and posterior leaflets. The anterior leaflet and the adjacentanterior chordae tendinae are captured between the first anterior taband the outer anterior surface of the ventricular skirt. The posteriorleaflet and the adjacent posterior chordae tendinae are captured betweenthe posterior tab and the posterior outer surface of the ventricularskirt.

In another aspect of the present invention, a method of delivering animplantable prosthetic valve to a patient's heart having a mitral valvewith an anterior leaflet and a posterior leaflet, comprises providing aprosthetic valve, wherein the prosthetic valve comprises an expandableframe having a first end, a second end opposite the first end, a firstanterior tab on an anterior portion of the expandable frame, a posteriortab on a posterior portion of the expandable frame, and a ventricularskirt adjacent the first end of the expandable frame. The prostheticvalve has an expanded configuration for engaging the heart and acollapsed configuration. The prosthetic valve is delivered in thecollapsed configuration to the patient's heart adjacent the mitralvalve. The first anterior tab is expanded radially outward such that atip portion of the first anterior tab engages a first fibrous trigone ona first side of the anterior leaflet of the mitral valve. The anteriorleaflet and adjacent anterior chordae tendineae are disposed between thefirst anterior tab and an outer anterior surface of the ventricularskirt. After radially expanding the first anterior tab, the ventricularskirt is radially expanded outward thereby engaging the anterior leafletsuch that the anterior leaflet and the adjacent anterior chordaetendinae are captured between the first anterior tab and the outeranterior surface of the ventricular skirt. After radially expanding theventricular skirt, the posterior tab is radially expanded outward suchthat the posterior leaflet of the mitral valve and adjacent posteriorchordae tendineae are disposed and captured between the posterior taband an outer posterior surface of the ventricular skirt.

The method may further comprise providing a delivery catheter, whereinthe prosthetic valve is releasably coupled thereto. Delivering theprosthetic valve may comprise transapical delivery of the prostheticvalve from a region outside the heart to the left ventricle of theheart, or the prosthetic valve may be delivered transseptally from theright atrium to the left atrium of the heart. Delivering the prostheticvalve may comprise positioning the prosthetic valve across the mitralvalve so that the first end of the expandable frame is inferior to aportion of the mitral valve and the second end of the expandable frameis superior to a portion of the mitral valve.

Expanding the first anterior tab may comprise retracting a constrainingsheath from the first anterior tab so that the first anterior tab isfree to self-expand radially outward. The prosthetic valve may furthercomprise a second anterior tab on the anterior portion of the expandableframe, and the method may further comprise expanding the second anteriortab radially outward such that a tip portion of the second anterior tabengages a second fibrous trigone on a second side of the anteriorleaflet opposite the first side of the anterior leaflet. The anteriorleaflet and adjacent anterior chordae tendineae may be disposed betweenthe second anterior tab and an outer surface of the ventricular skirt.The second anterior tab may expand radially outward concurrently withexpansion of the first anterior tab. Prior to engaging the first fibroustrigone or the second fibrous trigone with the respective first orsecond anterior tab, and prior to disposing the anterior leaflet and theadjacent chordae tendineae between the first or second anterior tab andthe outer surface of the ventricular skirt, the method may comprisepartially expanding the first or the second anterior tab radiallyoutward such that the first or the second anterior tab is transverse toa longitudinal axis of the prosthetic valve. Expanding the secondanterior tab may comprise retracting a constraining sheath from thesecond anterior tab so that the second anterior tab is free toself-expand radially outward.

In some embodiments, prior to disposing the posterior leaflet of themitral valve and the adjacent posterior chordae tendineae between theposterior tab and the outer posterior surface of the ventricular skirt,the method may comprise partially expanding the posterior tab radiallyoutward such that the posterior tab is transverse to a longitudinal axisof the prosthetic valve. After the anterior leaflet and the adjacentanterior chordae tendineae are disposed between the first anterior taband the outer anterior surface of the ventricular skirt, the method maycomprise partially expanding the posterior tab radially outward suchthat the posterior tab is transverse to a longitudinal axis of theprosthetic valve, and wherein the posterior tab is partially expandedwithout disposing the posterior leaflet of the mitral valve and theadjacent posterior chordae tendinae between the posterior tab and theouter posterior surface of the ventricular skirt.

Radially expanding the ventricular skirt may comprise retracting aconstraining sheath from the ventricular skirt so that the ventricularskirt is free to self-expand radially outward. The ventricular skirt maycomprise a plurality of barbs, and expanding the ventricular skirt maycomprise anchoring the plurality of barbs into heart tissue. Theprosthetic valve may further comprise a plurality of commissures, andexpanding the ventricular skirt may displace the anterior and posteriormitral valve leaflets radially outward thereby preventing interferencebetween the commissures and both of the anterior and posterior leaflets.Expanding the ventricular skirt may displace the anterior and posteriorvalve leaflets radially outward without contacting an inner wall of theleft ventricle, and without obstructing the left ventricular outflowtract. Expanding the ventricular skirt may expand the ventricular skirtasymmetrically such that an anterior portion of the ventricular skirt issubstantially flat, and a posterior portion of the ventricular skirt iscylindrically shaped.

The method may further comprise reducing or eliminating mitralregurgitation. In some embodiments, the prosthetic valve may carry atherapeutic agent, and the method may further comprise eluting thetherapeutic agent from the prosthetic valve into adjacent tissue. Theprosthetic valve may also comprise an alignment element. A secondfibrous trigone is disposed on a second side of the anterior leafletopposite the first side of the anterior leaflet, and the method mayfurther comprise aligning the alignment element with an aortic root anddisposing the alignment element between the first and second fibroustrigones. Aligning the alignment element may comprise rotating theprosthetic valve.

The prosthetic valve may further comprise a plurality of commissureswith a covering disposed thereover whereby a plurality of prostheticvalve leaflets are formed, and the method may further comprise releasingthe plurality of prosthetic valve leaflets from a delivery catheter. Theplurality of prosthetic valve leaflets may form a tricuspid valve thathas an open configuration and a closed configuration. The plurality ofprosthetic valve leaflets may be disposed away from one another in theopen configuration thereby permitting antegrade blood flow therethrough,and the plurality of prosthetic valve leaflets may engage one another inthe closed configuration thereby substantially preventing retrogradeblood flow therethrough.

The prosthetic valve may further comprise an atrial skirt, and themethod may further comprise expanding the atrial skirt radially outwardso as to lie over a superior surface of the mitral valve, and engagingthe atrial skirt against the superior surface of the mitral valve.Expanding the atrial skirt may comprise retracting a constraining sheathfrom the atrial skirt so that the atrial skirt is free to self-expandradially outward. The prosthetic valve may be moved upstream ordownstream relative to the mitral valve to ensure that the atrial skirtengages the superior surface of the mitral valve. Engaging the atrialskirt against the superior surface may seal the atrial skirt against thesuperior surface of the mitral valve to prevent or substantially preventblood flow therebetween.

The prosthetic valve may further comprise an annular region, and themethod may further comprise expanding the annular region radiallyoutward so as to conform with an annulus of the mitral valve, andengaging the annular region with the mitral valve annulus. Expanding theannular region may comprise retracting a constraining sheath from theannular region so that the annular region is free to self-expandradially outward. Expanding the annular region may compriseasymmetrically expanding the annular region such that an anteriorportion of the annular region is substantially flat, and a posteriorportion of the annular region is cylindrically shaped.

In another aspect of the present invention, a sequentially deployedprosthetic cardiac valve comprises a self-expanding frame having a firstend, a second end opposite the first end, an atrial region near thesecond end, and a ventricular region near the first end. Theself-expanding frame has an expanded configuration and a collapsedconfiguration. The expanded configuration is adapted to engage hearttissue, and the collapsed configuration is adapted to be delivered to apatient's heart. The prosthetic valve also includes a self-expandingatrial skirt disposed in the atrial region, a self-expanding ventricularskirt disposed in the ventricular region and a self-expanding annularregion disposed between the atrial region and the ventricular region. Afirst self-expanding anterior tab is disposed on an anterior portion ofthe self-expanding frame in the ventricular region. A self-expandingposterior tab is disposed on a posterior portion of the self-expandingframe in the ventricular region. A portion of the first self-expandinganterior tab and a portion of the self-expanding posterior tab partiallyself-expand radially outward when a constraint is removed therefrom. Thefirst anterior tab fully self-expands radially outward before theposterior tab fully self-expands radially outward when the constraint isremoved therefrom. The posterior tab fully self-expands radially outwardbefore ventricular skirt self-expands when the constraint is removedtherefrom, and the ventricular skirt fully expands last.

In another aspect of the present invention, a sequentially deployedprosthetic cardiac valve comprises a self-expanding frame having a firstend, a second end opposite the first end, an atrial region near thesecond end, and a ventricular region near the first end. Theself-expanding frame has an expanded configuration and a collapsedconfiguration. The expanded configuration is adapted to engage hearttissue, and the collapsed configuration is adapted to be delivered to apatient's heart. The prosthetic cardiac valve also comprises aself-expanding atrial skirt disposed in the atrial region, aself-expanding ventricular skirt disposed in the ventricular region, anda self-expanding annular region disposed between the atrial region andthe ventricular region. A first self-expanding anterior tab is disposedon an anterior portion of the self-expanding frame in the ventricularregion. A self-expanding posterior tab is disposed on a posteriorportion of the self-expanding frame in the ventricular region. A portionof the first self-expanding anterior tab and a portion of theself-expanding posterior tab partially self-expand radially outward whena constraint is removed therefrom. The first anterior tab self-expandsradially outward before the ventricular skirt self-expands radiallyoutward when the constraint is removed therefrom. The ventricular skirtself-expands radially outward before the posterior tab finishesself-expanding, and the posterior tab finishes self-expanding after theventricular skirt self-expands.

At least a portion of the atrial skirt may be covered with tissue or asynthetic material. The atrial skirt may have a collapsed configurationand an expanded configuration. The collapsed configuration may beadapted for delivery to a patient's heart, and the expandedconfiguration may be radially expanded relative to the collapsedconfiguration and may be adapted to lie over a superior surface of thepatient's native mitral valve, thereby anchoring the atrial skirtagainst a portion of the left atrium. The atrial skirt may comprise oneor more radiopaque markers and may comprise a plurality of axiallyoriented struts connected together with a connector element therebyforming interconnected struts into a series of peaks and valleys. Afterself-expansion of the atrial skirt, the atrial skirt may form a flangedregion adjacent the second end of the self-expanding frame. Also afterself-expansion, the atrial skirt may have an asymmetrically D-shapedcross-section having a substantially flat anterior portion, and acylindrically shaped posterior portion. The prosthetic valve may furthercomprise an alignment element coupled to an anterior portion of theatrial skirt, and the alignment element may be aligned with an aorticroot of a patient's heart and may be disposed between two fibroustrigones of an anterior leaflet of the patient's mitral valve.

At least a portion of the annular region may be covered with tissue or asynthetic material. The annular region may have a collapsedconfiguration and an expanded configuration. The collapsed configurationmay be adapted for delivery to the patient's heart, and the expandedconfiguration may be radially expanded relative to the collapsedconfiguration and may be adapted to conform with and adapted to engagean annulus of a patient's native mitral valve. After self-expanding, theannular region may have an asymmetrically D-shaped cross-section havinga substantially flat anterior portion, and a cylindrically shapedposterior portion. The annular region may comprise a plurality ofaxially oriented struts connected together with a connector element, andthe plurality of interconnected struts may form a series of peaks andvalleys. One or more of the plurality of axially oriented struts maycomprise one or more suture holes extending therethrough, and the sutureholes may be sized to receive a suture.

At least a portion of the ventricular skirt may be covered with tissueor a synthetic material. After self-expanding, the ventricular skirt maycomprise an asymmetrically D-shaped cross-section having a substantiallyflat anterior portion, and a cylindrically shaped posterior portion. Theventricular skirt may have a collapsed configuration and an expandedconfiguration. The collapsed configuration may be adapted for deliveryto the patient's heart, and the expanded configuration may be radiallyexpanded relative to the collapsed configuration and may be adapted todisplace native mitral valve leaflets radially outward.

The first anterior tab may have a tip portion adapted to engage a firstfibrous trigone on a first side of an anterior leaflet of a patient'smitral valve, and the first anterior tab may also be adapted to capturethe anterior leaflet and adjacent chordae tendineae between the firstanterior tab and an outer anterior surface of the ventricular skirt. Theprosthetic cardiac valve may further comprise a second self-expandinganterior tab disposed on the anterior portion of the self-expandingframe in the ventricular region. The second anterior tab may have a tipportion adapted to engage a second fibrous trigone on a second side ofthe anterior leaflet of the patient's mitral valve opposite the firstside of the anterior leaflet. The second anterior tab may be adapted tocapture the anterior leaflet and adjacent chordae tendineae between thesecond anterior tab and the outer surface of the ventricular skirt. Thefirst or the second anterior tabs may have a cover disposed thereoverthat increases the contact area between the tab and the cardiac tissue.The cover may include a fabric disposed over a polymer tab that iscoupled to the first or second tab. The posterior tab may be adapted tobeing anchored over a posterior leaflet of the patient's mitral valve,such that the posterior tab is seated between the posterior leaflet anda ventricular wall of a patient's heart. The posterior tab may comprisea plurality of struts, and adjacent struts may be coupled together toform a plurality of expandable hinged joints. Upon radial expansion ofthe posterior tab, the plurality of struts may move away from oneanother thereby opening the hinged joints forming an elongate horizontalsection which allows engagement and anchoring of the posterior tab withthe sub-annular region between the posterior leaflet and the ventricularwall. Thus, the elongate horizontal section contacts a larger region ofthe sub-annular region as compared with a posterior tab that only has atapered tip formed from a single hinge between struts. The ventricularskirt may further comprise a plurality of barbs coupled thereto. Theplurality of barbs may be adapted to anchor the ventricular skirt intoheart tissue. The ventricular skirt may also comprise a plurality ofstruts connected together with a connector element, and the plurality ofinterconnected struts may form a series of peaks and valleys. One ormore of the struts may comprise one or more suture holes extendingtherethrough, the suture holes sized to receive a suture.

The prosthetic cardiac valve may further comprise a plurality ofprosthetic valve leaflets. Each of the leaflets may have a first end anda free end, and the first end may be coupled with the self-expandingframe and the free end may be opposite of the first end. The prostheticvalve leaflets may have an open configuration in which the free ends ofthe prosthetic valve leaflets are disposed away from one another toallow antegrade blood flow therepast. The prosthetic valve leaflets mayhave a closed configuration in which the free ends of the prostheticvalve leaflets engage one another and substantially prevent retrogradeblood flow therepast. The plurality of prosthetic valve leaflets mayform a tricuspid valve. At least a portion of one or more prostheticvalve leaflets may comprise tissue or a synthetic material. One or moreof the prosthetic valve leaflets may comprise a commissure post having acommissure tab, and the commissure tab may be adapted to be releasablyengaged with a delivery device. The prosthetic cardiac valve may carry atherapeutic agent that is adapted to being eluted therefrom.

In still another aspect of the present invention, a delivery system fordelivering a prosthetic cardiac valve to a patient's heart having amitral valve with an anterior leaflet and a posterior leaflet, comprisesa prosthetic cardiac valve, an inner guidewire shaft having a lumenextending therethrough, where the lumen is sized to slidably receive aguidewire, and a distal tissue penetrating tip coupled to a distalportion of the inner guidewire shaft. The distal tip is adapted to passthrough and expand tissue in the heart, and a continuous flared regioncouples the inner guidewire shaft with the distal tip. The continuousflared region is configured to support the prosthetic cardiac valvethereby reducing or eliminating unwanted bending of the prostheticcardiac valve. The delivery system also comprises a hub shaftconcentrically disposed over the inner guidewire shaft. The prostheticcardiac valve is releasably coupled to a distal portion of the hubshaft. A bell shaft is slidably and concentrically disposed over the hubshaft, and an outer sheath is slidably and concentrically disposed overthe bell shaft. The prosthetic cardiac valve is housed in the outersheath in a radially collapsed configuration. The delivery system alsohas a handle near a proximal end of the delivery system. The handlecomprises an actuator mechanism adapted to advance and retract the bellshaft and the sheath. Proximal retraction of the outer sheath relativeto the bell shaft may remove a constraint from the prosthetic cardiacvalve thereby allowing the prosthetic cardiac valve to self-expand intoengagement with the patient's mitral valve. The prosthetic cardiac valvemay comprise a plurality of commissure posts, and the commissure postsmay be releasably coupled with a distal portion of the hub shaft.Proximal retraction of the bell shaft relative to the hub shaft allowsthe commissure posts to uncouple from the hub shaft. The actuatormechanism may comprise a rotatable wheel.

These and other embodiments are described in further detail in thefollowing description related to the appended drawing figures.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

The novel features of the invention are set forth with particularity inthe appended claims. A better understanding of the features andadvantages of the present invention will be obtained by reference to thefollowing detailed description that sets forth illustrative embodiments,in which the principles of the invention are utilized, and theaccompanying drawings of which:

FIG. 1 is a schematic illustration of the left ventricle of a heartshowing blood flow during systole with arrows.

FIG. 2 is a schematic illustration of the left ventricle of a hearthaving prolapsed leaflets in the mitral valve.

FIG. 3 is a schematic illustration of a heart in a patient sufferingfrom cardiomyopathy where the heart is dilated and the leaflets do notmeet.

FIG. 3A shows normal closure of the valve leaflets.

FIG. 3B shows abnormal closure of the valve leaflets.

FIG. 4 illustrates mitral valve regurgitation in the left ventricle of aheart having impaired papillary muscles.

FIGS. 5A-5B illustrate anatomy of the mitral valve.

FIG. 6 illustrates an exemplary embodiment of an uncovered frame in aprosthetic cardiac valve, with the frame flattened out and unrolled.

FIG. 7 illustrates another exemplary embodiment of an uncovered frame ina prosthetic cardiac valve, with the frame flattened out and unrolled.

FIG. 8 illustrates still another exemplary embodiment of an uncoveredframe in a prosthetic cardiac valve, with the frame flattened out andunrolled.

FIG. 9A illustrates a perspective view of an uncovered frame in aprosthetic cardiac valve after it has expanded.

FIG. 9B illustrates a top view of the embodiment in FIG. 9A.

FIG. 10 illustrates the frame of FIG. 9A with the covering therebyforming a prosthetic cardiac valve.

FIGS. 11A-11D illustrate an exemplary embodiment of a delivery systemused to transapically deliver a prosthetic cardiac valve.

FIGS. 12A-12L illustrate an exemplary method of implanting a prostheticcardiac valve.

FIGS. 13A-13L illustrate another exemplary method of implanting aprosthetic cardiac valve.

FIGS. 14A-14D illustrate an exemplary embodiment of a tab covering.

DETAILED DESCRIPTION OF THE INVENTION

Specific embodiments of the disclosed device, delivery system, andmethod will now be described with reference to the drawings. Nothing inthis detailed description is intended to imply that any particularcomponent, feature, or step is essential to the invention.

Cardiac Anatomy. The left ventricle LV of a normal heart H in systole isillustrated in FIG. 1. The left ventricle LV is contracting and bloodflows outwardly through the aortic valve AV, a tricuspid valve in thedirection of the arrows. Back flow of blood or “regurgitation” throughthe mitral valve MV is prevented since the mitral valve is configured asa “check valve” which prevents back flow when pressure in the leftventricle is higher than that in the left atrium LA. The mitral valve MVcomprises a pair of leaflets having free edges FE which meet evenly toclose, as illustrated in FIG. 1. The opposite ends of the leaflets LFare attached to the surrounding heart structure along an annular regionreferred to as the annulus AN. The free edges FE of the leaflets LF aresecured to the lower portions of the left ventricle LV through chordaetendineae CT (also referred to herein as the chordae) which include aplurality of branching tendons secured over the lower surfaces of eachof the valve leaflets LF. The chordae CT in turn, are attached to thepapillary muscles PM which extend upwardly from the lower portions ofthe left ventricle and interventricular septum IVS.

Referring now to FIGS. 2-4, a number of structural defects in the heartcan cause mitral valve regurgitation. Ruptured chordae RCT, as shown inFIG. 2, can cause a valve leaflet LF2 to prolapse since inadequatetension is transmitted to the leaflet via the chordae. While the otherleaflet LF1 maintains a normal profile, the two valve leaflets do notproperly meet and leakage from the left ventricle LV into the leftatrium LA will occur, as shown by the arrow.

Regurgitation also occurs in the patients suffering from cardiomyopathywhere the heart is dilated and the increased size prevents the valveleaflets LF from meeting properly, as shown in FIG. 3. The enlargementof the heart causes the mitral annulus to become enlarged, making itimpossible for the free edges FE to meet during systole. The free edgesof the anterior and posterior leaflets normally meet along a line ofcoaptation C as shown in FIG. 3A, but a significant gap G can be left inpatients suffering from cardiomyopathy, as shown in FIG. 3B.

Mitral valve regurgitation can also occur in patients who have sufferedischemic heart disease where the functioning of the papillary muscles PMis impaired, as illustrated in FIG. 4. As the left ventricle LVcontracts during systole, the papillary muscles PM do not contractsufficiently to effect proper closure. The leaflets LF1 and LF2 thenprolapse, as illustrated. Leakage again occurs from the left ventricleLV to the left atrium LA, as shown by the arrow.

FIG. 5A more clearly illustrates the anatomy of a mitral valve MV whichis a bicuspid valve having an anterior side ANT and a posterior sidePOST. The valve includes an anterior (aortic) leaflet AL and a posterior(mural) leaflet PL. Chordae tendineae CT couple the valve leaflets AL,PL with the antero-lateral papillary muscle ALPM and the postero-medialpapillary muscle PMPM. The valve leaflets AL, PL join one another alonga line referred to as the antero-lateral commissure ALC and theposterior-medial commissure PMC. The annulus AN circumscribes the valveleaflets, and two regions adjacent an anterior portion of the annulus,on opposite sides of the anterior leaflet are referred to as the leftfibrous trigone LFT and also the right fibrous trigone RFT. These areasare indicted generally by the solid triangles. FIG. 5B more clearlyillustrates the left and right fibrous trigones, LFT, RFT.

While various surgical techniques as well as implantable devices havebeen proposed and appear to be promising treatments for mitralregurgitation, surgical approaches can require a lengthy recoveryperiod, and implantable devices have varying clinical results.Therefore, there still is a need for improved devices and methods fortreating mitral regurgitation. While the embodiments disclosed hereinare directed to an implantable prosthetic mitral valve for treatingmitral regurgitation, one of skill in the art will appreciate that thisis not intended to be limiting, and the device and methods disclosedherein may also be used to treat other cardiac valves such as thetricuspid valve, aortic valve, pulmonary valve, etc, as well as othervalves in the body such as venous valves.

Prosthetic Valve. Prosthetic valves have been surgically implanted inthe heart as a treatment for mitral regurgitation. Some of these valveshave been valves harvested from animals such as porcine valves, andothers have been prosthetic mechanical valves with or without a tissuecovering. More recently, minimally invasive catheter technology has beenused to deliver prosthetic valves to the heart. These valves typicallyinclude an anchor for securing the valve to the patient's heart, and avalve mechanism, either a mechanical valve, a valve with animal tissue,or combinations thereof. The prosthetic valve once implanted, takes overfor the malfunctioning native valve, thereby reducing or eliminatingvalvar insufficiency. While some of these valves appear promising, therestill is a need for improved valves. Positioning and anchoring theprosthetic valve in the native anatomy remains a challenge. Thefollowing specification discloses exemplary embodiments of a prostheticvalve, a delivery system for the prosthetic valve, and methods ofdelivering the valve that overcome some of the challenges associatedwith existing prosthetic valves.

FIG. 6 illustrates an exemplary embodiment of a prosthetic cardiac valvein the collapsed configuration. Coverings from the frame (e.g. fabric ortissue) has been removed to permit observation of the underlying frame600. The frame has been unrolled and flattened out. The prosthetic valveframe 600 has an atrial region 606, an annular region 608, and aventricular region 610. The frame 600 is formed from a plurality ofinterconnected struts that form a series of peaks and valleys which canexpand and contract relative to one another thereby permitting the frameto be loaded onto a delivery catheter in a collapsed configuration, andthen radially expanded at a target treatment site for implantation.Preferred embodiments are self-expanding and may be fabricated usingsuperelastic nitinol or other self-expanding materials. Shape memoryalloys that spring open above a transition temperature may also be used,and expandable members may also be used to expand the frame when plasticdeformation (e.g. balloon expansion) is required to open the frame.

Atrial region 606 has a skirt 616 which includes a plurality ofinterconnected struts that form a series of peaks and valleys. In thisregion, the struts are skewed relative to one another and thus theresulting cell pattern has an enlarged end and the opposite end tapersto a smaller end. In preferred embodiments, the anterior portion of theatrial skirt does not have a flanged region like the posterior portion,thus the anterior portion 602 of the atrial region may have shorterstruts than the posterior region 604. Thus the peaks and valleys in theanterior portion are axially offset from those in the remainingposterior portion of the atrial region. This may be advantageous as itprevents the struts in the anterior portion of the atrial skirt fromprotruding upwards potentially impinging against the left atrium andcausing perforations. Additionally, the shortened struts and offsetpeaks and valleys form an alignment element 614 that can assist thephysician with visualization of delivery of the prosthetic valve to themitral valve and also with alignment of the prosthetic valve prior toexpansion of the prosthetic valve. Optional radiopaque markers 614 a aredisposed on either side of the offset peaks and valleys and further helpwith visualization during implantation of the valve. The atrial regionpreferably self-expands to either a cylindrical shape, or it may have aD-shaped cross-section where the anterior portion 602 is substantiallyflat, and the posterior portion 604 is cylindrically shaped. This allowsthe atrial skirt to conform to the anatomy of the native mitral valve,thereby preventing obstruction of the left ventricular outflow tract.Additionally, the atrial skirt may also be formed so that uponexpansion, the skirt flares outward and forms a flange that can restagainst a superior surface of the mitral valve. The flanged region ispreferably along the posterior portion of the atrial skirt, and theanterior portion of the atrial skirt remains flangeless. Or, the flangemay extend entirely around the atrial skirt. The atrial region isconnected to the adjacent annular region 608 with connecting strutswhich are preferably linear and substantially parallel to thelongitudinal axis of the frame.

The annular region 608 is also comprised of a plurality of axiallyoriented and interconnected struts that form peaks and valleys thatallow radial expansion. The struts are preferably parallel with oneanother and parallel with the longitudinal axis of the frame. Theannular region may also be self-expanding and expand into a cylindricalshape, or more preferably the annular region may expand to have aD-shaped cross-section as described above with respect to the atrialregion. Thus, the annular region may similarly have a flat anteriorportion, and a cylindrically shaped posterior portion. Upon delivery,the annular region is aligned with and expanded into engagement with themitral valve annulus. Connector struts join the annular region with theventricular region 610.

The ventricular region 610 also includes a plurality of interconnectedstruts that form peaks and valleys. Additionally, the struts in theventricular region form the leaflet commissures 613 which are coveredwith fabric, pericardial tissue, or other materials to form theprosthetic valve leaflets. Holes in the commissures allow suture to beattached thereto. Struts in the ventricular region also form aventricular skirt 628 which expands outward to engage the anterior andposterior mitral valve leaflets, and struts in the ventricular regionalso form the anterior tabs 624 and the posterior tab 630. The anteriortabs are designed to capture the anterior mitral valve leaflet betweenan inner surface of the anterior tab and outer surface of theventricular skirt. Any adjacent chordae tendineae may also be capturedtherebetween. Also, the tip of the anterior tab engages the fibroustrigone on an anterior portion of the mitral valve, one on the left andone on the right side. The posterior tab similarly captures theposterior mitral valve leaflet between an inner surface of the posteriortab and an outer surface of the ventricular skirt, along with anyadjacent chordae tendineae. This will be described in more detail below.

By controlling strut length or axial position of the anterior orposterior tabs along the frame, deployment of the tabs may becontrolled. Thus in this exemplary embodiment, because the length of thestruts in the anterior tabs and posterior tabs 624, 630 as well as theirrelative position along the frame are the same as one another, when aconstraining sheath is retracted away from the tabs, the anterior andposterior tabs will partially spring outward together. As theconstraining sheath is further retracted, the remainder of the anteriortabs will self-expand radially outward. Further retraction of theconstraining sheath then allows the remainder of the posterior tab tofinish it's radial expansion, and finally the ventricular skirt willradially expand outward. While strut lengths and axial position of theposterior tab and the ventricular skirt are similar, internal strutsconnect the ventricular skirt with the commissures, and this delaysexpansion of the ventricular skirt slightly, thus the posterior tabfinishes expansion before the ventricular skirt. Using this sequence ofdeploying the prosthetic valve may allow the valve to more accurately bedelivered and also more securely anchored into position.

Suture holes 621 are disposed along the struts of the annular region aswell as the ventricular region to allow attachment of a cover such aspericardium or a polymer such as Dacron or ePTFE. The suture holes mayalso be disposed along any other part of the frame. Barbs 623 aredisposed along the ventricular skirt 628 to help anchor the prostheticvalve to adjacent tissue. Commissure tabs or tabs 612 are disposed onthe tips of the commissures 613 and may be used to releasably couple thecommissures with a delivery system as will be described below. Thisallows the frame to expand first, and then the commissures may bereleased from the delivery system afterwards. One of skill in the artwill appreciate that a number of strut geometries may be used, andadditionally that strut dimensions such as length, width, thickness,etc. may be adjusted in order to provide the prosthesis with the desiredmechanical properties such as stiffness, radial crush strength,commissure deflection, etc. Therefore, the illustrated geometry is notintended to be limiting.

The frame may be formed by electrical discharge machining (EDM), lasercutting, photochemical etching, or other techniques known in the art.Hypodermic tubing or flat sheets may be used to form the frame. Once theframe has been cut and formed into a cylinder (if required), it may beradially expanded into a desired geometry and heat treated using knownprocesses to set the shape. Thus, the prosthetic valve may be loadedonto a delivery catheter in a collapsed configuration and constrained inthe collapsed configuration with a constraining sheath. Removal of theconstraining sheath will allow the prosthesis to self-expand into itsunbiased pre-set shape. In other embodiments, an expandable member suchas a balloon may be used to radially expand the prosthesis into itspreferred expanded configuration.

FIG. 7 illustrates another exemplary embodiment of a prosthetic cardiacvalve in the collapsed configuration, and similar to the previousembodiment with the major difference being the strut lengths in theanterior tabs, posterior tab, and ventricular skirt. Varying the strutlengths allow the sequence of expansion of the anterior and posteriortabs and ventricular skirt to be controlled. Coverings from the frame(e.g. fabric or tissue) has been removed to permit observation of theunderlying frame 700. The frame has been unrolled and flattened out. Theprosthetic valve frame 700 has an atrial region 706, an annular region708, and a ventricular region 710. The frame 700 is formed from aplurality of interconnected struts that form a series of peaks andvalleys which can expand and contract relative to one another therebypermitting the frame to be loaded onto a delivery catheter in acollapsed configuration, and then radially expanded at a targettreatment site for implantation. Preferred embodiments areself-expanding and may be fabricated using superelastic nitinol or otherself-expanding materials. Shape memory alloys that spring open above atransition temperature may also be used, and expandable members may alsobe used to expand the frame when plastic deformation (e.g. balloonexpansion) is required to open the frame.

Atrial region 706 has a skirt 716 which includes a plurality ofinterconnected struts that form a series of peaks and valleys. In thisregion, the struts are skewed relative to one another and thus theresulting cell pattern has an enlarged end and the opposite end tapersto a smaller end. An anterior portion 702 of the atrial region hasshorter struts than the posterior region 704. Thus the peaks and valleysin the anterior portion are axially offset from those in the remainingposterior portion of the atrial region. This allows creation of analignment element 714 to help the physician deliver the prosthetic valveto the mitral valve and align the prosthetic valve prior to expansion ofthe prosthetic valve. Other aspects of the atrial region 706 are similarto those of the atrial region 606 in FIG. 6. Optional radiopaque markers714 a are disposed on either side of the offset peaks and valleys andhelp with visualization during implantation of the valve. The atrialregion preferably self-expands to either a cylindrical shape, or it mayhave a D-shaped cross-section where the anterior portion 702 issubstantially flat, and the posterior portion 704 is cylindricallyshaped. This allows the atrial skirt to conform to the anatomy of thenative mitral valve, thereby preventing obstruction of the leftventricular outflow tract. Additionally, the atrial skirt may also beformed so that upon expansion, the skirt flares outward and forms aflange that can rest against a superior surface of the mitral valve. Theflanged region is preferably along the posterior portion of the atrialskirt, and the anterior portion of the atrial skirt remains flangeless.Or, the flange may extend entirely around the atrial skirt. The atrialregion is connected to the adjacent annular region 708 with connectingstruts which are preferably linear and substantially parallel to thelongitudinal axis of the frame.

The annular region 708 is also comprised of a plurality of axiallyoriented and interconnected struts that form peaks and valleys thatallow radial expansion. The struts are preferably parallel with oneanother and parallel with the longitudinal axis of the frame. Theannular region may also be self-expanding and expand into a cylindricalshape, or more preferably the annular region may expand to have aD-shaped cross-section as described above with respect to the atrialregion. Thus, the annular region may similarly have a flat anteriorportion, and a cylindrically shaped posterior portion. Upon delivery,the annular region is aligned with and expanded into engagement with themitral valve annulus. Connector struts join the annular region with theventricular region 710.

The ventricular region 710 also includes a plurality of interconnectedstruts that form peaks and valleys. Additionally, the struts in theventricular region form the leaflet commissures 713 which are coveredwith fabric, pericardial tissue, or other materials to form theprosthetic valve leaflets. Holes in the commissures allow suture to beattached thereto. Struts in the ventricular region also form aventricular skirt 728 which expands outward to engage the anterior andposterior mitral valve leaflets, and struts in the ventricular regionalso form the anterior tabs 724 and the posterior tab 730. The anteriortabs are designed to capture the anterior mitral valve leaflet betweenan inner surface of the anterior tab and outer surface of theventricular skirt. Any adjacent chordae tendineae may also be capturedtherebetween. Also, the tip of the anterior tab engages the fibroustrigone on an anterior portion of the mitral valve, one on the left andone on the right side. The posterior tab similar captures the posteriormitral valve leaflet between an inner surface of the posterior tab andan outer surface of the ventricular skirt, along with any adjacentchordae tendineae. This will be described in more detail below.

By controlling strut length or axial position of the anterior orposterior tabs along the frame, deployment of the tabs may becontrolled. Thus in this exemplary embodiment, because the length of thestruts in the anterior tabs and posterior tabs 724, 730 as well as theirrelative position along the frame are the same as one another, when aconstraining sheath is retracted away from the tabs, the anterior andposterior tabs will partially spring outward together. As theconstraining sheath is further retracted, the remainder of the anteriortabs will self-expand radially outward because they are the shortestrelative to the struts in the ventricular skirt and the posterior tab.Further retraction of the constraining sheath then allows theventricular skirt to radially expand, and finally further retraction ofthe sheath allows the remainder of the posterior tab to finish it'sradial expansion. Using this sequence of deploying the prosthetic valvemay allow the valve to more accurately be delivered and also moresecurely anchored into position.

Suture holes 721 are disposed along the struts of the annular region aswell as the ventricular region to allow attachment of a cover such aspericardium or a polymer such as Dacron or ePTFE. The suture holes mayalso be disposed along any other part of the frame. Barbs 723 aredisposed along the ventricular skirt 728 to help anchor the prostheticvalve to adjacent tissue. Commissure tabs or tabs 712 are disposed onthe tips of the commissures 713 and may be used to releasably couple thecommissures with a delivery system as will be described below. Thisallows the frame to expand first, and then the commissures may bereleased from the delivery system afterwards. One of skill in the artwill appreciate that a number of strut geometries may be used, andadditionally that strut dimensions such as length, width, thickness,etc. may be adjusted in order to provide the prosthesis with the desiredmechanical properties such as stiffness, radial crush strength,commissure deflection, etc. Therefore, the illustrated geometry is notintended to be limiting. The frame may be formed similarly as describedabove with respect to FIG. 6.

FIG. 8 illustrates another exemplary embodiment of a prosthetic cardiacvalve in the collapsed configuration, and is similar to the previousembodiments, with the major difference being that the posterior tab isdesigned to expand to form an elongate horizontal section which allowsengagement and anchoring of the posterior tab with the sub-annularregion between the posterior leaflet and the ventricular wall. Thus, theelongate horizontal section contacts a larger region of the sub-annularregion as compared with a posterior tab that only has a tapered tipformed from a single hinge between struts. This provides enhancedanchoring of the prosthetic valve. In this exemplary embodiment, theanterior tabs will completely self-expand first, followed by theposterior tab and then the ventricular skirt. However, in somesituations external factors such as the delivery system, anatomy, etc.may alter the sequence of expansion, and therefore this is not intendedto be limiting. Coverings from the frame (e.g. fabric or tissue) havebeen removed to permit observation of the underlying frame 800. Theframe has been unrolled and flattened out. The prosthetic valve frame800 has an atrial region 806, an annular region 808, and a ventricularregion 810. The frame 800 is formed from a plurality of interconnectedstruts that form a series of peaks and valleys which can expand andcontract relative to one another thereby permitting the frame to beloaded onto a delivery catheter in a collapsed configuration, and thenradially expanded at a target treatment site for implantation. Preferredembodiments are self-expanding and may be fabricated using superelasticnitinol or other self-expanding materials. Shape memory alloys thatspring open above a transition temperature may also be used, andexpandable members may also be used to expand the frame when plasticdeformation (e.g. balloon expansion) is required to open the frame.

Atrial region 806 has a skirt 816 which includes a plurality ofinterconnected struts that form a series of peaks and valleys. In thisregion, the struts are skewed relative to one another and thus theresulting cell pattern has an enlarged end and the opposite end tapersto a smaller end. An anterior portion 802 of the atrial region hasshorter struts than the posterior region 804. Thus the peaks and valleysin the anterior portion are axially offset from those in the remainingposterior portion of the atrial region. This allows creation of analignment element 814 to help the physician deliver the prosthetic valveto the mitral valve and align the prosthetic valve prior to expansion ofthe prosthetic valve. Other aspects of the atrial region 806 are similarto those of the atrial region 606 in FIG. 6. Optional radiopaque markers814 a are disposed on either side of the offset peaks and valleys andhelp with visualization during implantation of the valve. The atrialregion preferably self-expands to either a cylindrical shape, or it mayhave a D-shaped cross-section where the anterior portion 802 issubstantially flat, and the posterior portion 804 is cylindricallyshaped. This allows the atrial skirt to conform to the anatomy of thenative mitral valve, thereby preventing obstruction of the leftventricular outflow tract. Additionally, the atrial skirt may also beformed so that upon expansion, the skirt flares outward and forms aflange that can rest against a superior surface of the mitral valve. Theflanged region is preferably along the posterior portion of the atrialskirt, and the anterior portion of the atrial skirt remains flangeless.Or, the flange may extend entirely around the atrial skirt. The atrialregion is connected to the adjacent annular region 808 with connectingstruts which are preferably linear and substantially parallel to thelongitudinal axis of the frame.

The annular region 808 is also comprised of a plurality of axiallyoriented and interconnected struts that form peaks and valleys thatallow radial expansion. The struts are preferably parallel with oneanother and parallel with the longitudinal axis of the frame. Theannular region may also be self-expanding and expand into a cylindricalshape, or more preferably the annular region may expand to have aD-shaped cross-section as described above with respect to the atrialregion. Thus, the annular region may similarly have a flat anteriorportion, and a cylindrically shaped posterior portion. Upon delivery,the annular region is aligned with and expanded into engagement with themitral valve annulus. Connector struts join the annular region with theventricular region 810.

The ventricular region 810 also includes a plurality of interconnectedstruts that form peaks and valleys. Additionally, the struts in theventricular region form the leaflet commissures 813 which are coveredwith fabric, pericardial tissue, or other materials to form theprosthetic valve leaflets. Holes in the commissures allow suture to beattached thereto. Struts in the ventricular region also form aventricular skirt 828 which expands outward to engage the anterior andposterior mitral valve leaflets, and struts in the ventricular regionalso form the anterior tabs 824 and the posterior tab 830. The anteriortabs are designed to capture the anterior mitral valve leaflet betweenan inner surface of the anterior tab and outer surface of theventricular skirt. Any adjacent chordae tendineae may also be capturedtherebetween. Also, the tip of the anterior tab engages the fibroustrigone on an anterior portion of the mitral valve, one on the left andone on the right side. The posterior tab similarly captures theposterior mitral valve leaflet between an inner surface of the posteriortab and an outer surface of the ventricular skirt, along with anyadjacent chordae tendineae. This will be described in more detail below.The posterior tab is similar to the posterior tabs described above inFIGS. 6-7, except that in this embodiment, the posterior tab comprisesfour interconnected struts as opposed to two interconnected struts.Thus, in this embodiment the plurality of interconnected struts formthree hinged regions 836 along the tab. Upon expansion of the posteriortab, the hinged regions will also expand, thereby forming an elongatehorizontal section which allows engagement and anchoring of theposterior tab with the sub-annular region between the posterior leafletand the ventricular wall. This may help position and anchor theprosthetic valve better than posterior tabs which only have a smallerfootprint or a single tapered tip for engagement with the posteriorportion of the mitral valve. The posterior tab in this embodiment, maybe substituted with any of the other posterior tabs described in thisspecification.

By controlling strut length or axial position of the anterior orposterior tabs along the frame, deployment of the tabs may becontrolled. Thus in this exemplary embodiment, because the length of thestruts in the anterior tabs and posterior tabs 824, 830 as well as theirrelative position along the frame are the same as one another, when aconstraining sheath is retracted away from the tabs, the anterior andposterior tabs will partially spring outward together. As theconstraining sheath is further retracted, the remainder of the anteriortabs will self-expand radially outward because they are the shortestrelative to the struts in the ventricular skirt and the posterior tab.Further retraction of the constraining sheath then allows the remainderof the posterior tab to finish self-expanding, followed byself-expansion of the ventricular skirt. Using this sequence ofdeploying the prosthetic valve may allow the valve to more accurately bedelivered and also more securely anchored into position.

Suture holes 821 are disposed along the struts of the annular region aswell as the ventricular region to allow attachment of a cover such aspericardium or a polymer such as Dacron or ePTFE. The suture holes mayalso be disposed along any other part of the frame. Barbs 823 aredisposed along the ventricular skirt 828 to help anchor the prostheticvalve to adjacent tissue. Commissure tabs or tabs 812 are disposed onthe tips of the commissures 813 and may be used to releasably couple thecommissures with a delivery system as will be described below. Thisallows the frame to expand first, and then the commissures may bereleased from the delivery system afterwards. One of skill in the artwill appreciate that a number of strut geometries may be used, andadditionally strut dimensions such as length, width, thickness, etc. maybe adjusted in order to provide the prosthesis with the desiredmechanical properties such as stiffness, radial crush strength,commissure deflection, etc. Therefore, the illustrated geometry is notintended to be limiting. The frame may be formed similarly as describedabove.

FIG. 9A illustrates the frame 900 of a prosthetic cardiac valve after ithas expanded. Any of the frame embodiments described above may take thisform as each of the above frames have similar geometry but they expandin different order. The frame includes the atrial skirt 906 withanterior portion 914 and posterior portion 916. A flanged region isformed around the posterior portion and the anterior portion remainsflangeless. Additionally, the anterior portion is generally flat, whilethe posterior portion is cylindrically shaped, thereby forming aD-shaped cross-section which accommodates the mitral valve anatomy. FIG.9B is a top view of the embodiment in FIG. 9A and more clearlyillustrates the D-shaped cross-section.

The frame also includes the annular region 910 and ventricular skirt912. Anterior tabs 904 (only one visible in this view) is fully expandedsuch that a space exists between the inner surface of the anterior taband an outer surface of the ventricular skirt. This allows the anteriorleaflet and adjacent chordae to be captured therebetween. Similarly, theposterior tab 902 is also fully deployed, with a similar space betweenthe inner surface of the posterior tab 902 and an outer surface of theventricular skirt. This allows the posterior leaflet and adjacentchordae tendineae to be captured therebetween. The commissure posts 908are also visible and are disposed in the inner channel formed by theframe. The commissure posts are used to form the prosthetic mitral valveleaflets. The overall shape of the expanded frame is D-shaped, with theanterior portion flat and the posterior portion cylindrically shaped.

FIG. 10 illustrates the expanded frame covered with a cover 1002 such aspericardial tissue or a polymer such as ePTFE or a fabric like Dacronattached to the frame, thereby forming the prosthetic cardiac valve1000. The atrial skirt may be entirely covered by a material, or inpreferred embodiments, the covering is only disposed between adjacentstruts 1012 in adjacent cells in the flanged portion of the atrialskirt. The area 1014 between adjacent struts within the same cell remainuncovered. This allows blood flow to remain substantially uninterruptedwhile the prosthetic valve is being implanted. Suture 1010 may be usedto attach the cover to the frame. In this view, only the posterior tab1006 is visible on the posterior portion of the prosthetic valve alongwith ventricular skirt 1008 and atrial skirt 1004.

Delivery System. FIGS. 11A-11D illustrate an exemplary embodiment of adelivery system that may be used to deliver any of the prostheticcardiac valves disclosed in this specification. While the deliverysystem is designed to preferably deliver the prosthetic cardiac valvetransapically, one of skill in the art will appreciate that it may alsobe modified so that the prosthetic valve may be delivered via a cathetertransluminally, such using a transseptal route. One of skill in the artwill appreciate that using a transseptal route may require the relativemotion of the various shafts to be modified in order to accommodate theposition of the delivery system relative to the mitral valve.

FIG. 11A illustrates a perspective view of delivery system 1100. Thedelivery system 1100 includes a handle 1112 near a proximal end of thedelivery system and a distal tissue penetrating tip 1110. Four elongateshafts are included in the delivery system and include an outer sheathcatheter shaft 1102, a bell catheter shaft 1104 which is slidablydisposed in the outer sheath catheter shaft 1102, a hub catheter shaft1106 which remains stationary relative to the other shafts, but the bellcatheter shaft slides relative to the hub shaft, and finally an innerguidewire catheter shaft 1108 which is also fixed relative to the othershafts and has a lumen sized to receive a guidewire which passestherethrough and exits the distal tissue penetrating tip. An actuatormechanism 1114 is used to control movement of the various shafts as willbe explained in greater detail below, and flush lines 1116, 1118 withluer connectors are used to flush the annular regions between adjacentshafts. Flush line 1118 is used to flush the annular space between theouter sheath catheter shaft 1102 and the bell catheter shaft 1104. Flushline 1116 is used to flush the annular space between the bell catheter1104 and the hub catheter 1106. The inner guidewire catheter shaft 1108is stationary relative to the hub catheter 1106 therefore the annularspace may be sealed with an o-ring or other material. Luer connector1122 allows flushing of the guidewire lumen and a hemostatic valve suchas a Tuohy-Borst may be coupled to the luer connector to allow aguidewire to be advanced through the guidewire catheter shaft whilemaintaining hemostasis. Screws 1120 keep the handle housing coupledtogether. FIG. 11B illustrates a side view of the delivery system 1100.

FIG. 11C is a partial exploded view of the delivery system 1100 and moreclearly illustrates the components in the handle 1112 and how theyinteract. The handle 1112 includes a housing having two halves 1112 a,1112 b which hold all the components. The handle is preferably heldtogether with screws 1120 and nuts 1120 b, although it may also besealed using other techniques such as a press fit, snap fit, adhesivebonding, ultrasonic welding, etc. Rotation of actuator wheel 1114 istranslated into linear motion of threaded insert 1124. The outer sheathcatheter shaft 1102 is coupled to the threaded insert 1124, thereforerotation of actuator wheel 1114 in one direction will advance the sheathcatheter shaft 1102, and rotation in the opposite direction will retractthe sheath catheter shaft 1102. Further rotation of actuator wheel 1114retracts threaded insert 1124 enough to bump into pins 1126 which arecoupled to insert 1128, thereby also moving insert 1128. The bellcatheter shaft 1106 is coupled to insert 1128, therefore furtherrotation of the actuator wheel 1114 will move the outer shaft 1102 andalso move the bell catheter shaft 1106. Rotation of the actuator wheelin the opposite direction advances the sheath and threaded insert 1124disengages from pins 1126. Spring 1130 returns insert 1128 to itsunbiased position, thereby returning the bell catheter shaft to itsunbiased position.

Any of the prosthetic cardiac valves disclosed herein may be carried bydelivery system 1100. The atrial skirt, annular skirt, anterior tabs,posterior tab and ventricular skirt are loaded over the bell cathetershaft and disposed under the outer sheath catheter shaft 1102. Theventricular skirt is loaded proximally so that it is closest to thehandle 1112 and the atrial skirt is loaded most distally so it isclosest to the tip 1110. Therefore, retraction of outer sheath cathetershaft 1102 plays a significant part in controlling deployment of theprosthetic cardiac valve. The atrial skirt therefore expands first whenthe outer sheath catheter is retracted. The prosthetic valve commissuresmay be coupled with a hub 1106 a on the distal portion of hub catheter1106 and then the bell catheter shaft is disposed thereover, therebyreleasably engaging the commissures with the delivery catheter. Onceother portions of the prosthetic cardiac valve have expanded, thecommissures may be released.

FIG. 11D highlights the distal portion of the delivery system 1100.Outer sheath catheter shaft 1102 advances and retracts relative to bellcatheter shaft 1104 which is slidably disposed in the outer sheathcatheter shaft 1102. Hub catheter shaft 1106 is shown slidably disposedin bell catheter shaft 1104 and with bell catheter shaft 1104 retractedso as to expose the hub 1106 a having slots 1106 b that hold theprosthetic valve commissures. Inner guidewire catheter shaft 1108 is theinnermost shaft and has a tapered conical section 1130 which provides asmooth transition for the prosthetic valve and prevents unwanted bendingor buckling of the prosthetic cardiac valve frame. Tissue penetratingtip 1110 is adapted to penetrate tissue, especially in a cardiactransapical procedure.

Delivery Method. A number of methods may be used to deliver a prostheticcardiac valve to the heart. Exemplary methods of delivering a prostheticmitral valve may include a transluminal delivery route which may also bea transseptal technique which crosses the septum between the right andleft sides of the heart, or in more preferred embodiments, a transapicalroute may be used such as illustrated in FIGS. 12A-12L. The deliverydevice previously described above may be used to deliver any of theembodiments of prosthetic valves described herein, or other deliverydevices and other prosthetic valves may also be used, such as thosedisclosed in U.S. patent application Ser. No. 13/096,572, previouslyincorporated herein by reference. However, in this preferred exemplaryembodiment, the prosthetic cardiac valve of FIG. 6 is used so that theanterior tabs deploy first, followed by the posterior tab, and then theventricular skirt.

FIG. 12A illustrates the basic anatomy of the left side of a patient'sheart including the left atrium LA and left ventricle LV. Pulmonaryveins PV return blood from the lungs to the left atrium and the blood isthen pumped from the left atrium into the left ventricle across themitral valve MV. The mitral valve includes an anterior leaflet AL on ananterior side A of the valve and a posterior leaflet PL on a posteriorside P of the valve. The leaflets are attached to chordae tendineae CTwhich are subsequently secured to the heart walls with papillary musclesPM. The blood is then pumped out of the left ventricle into the aorta Aowith the aortic valve AV preventing regurgitation.

FIG. 12B illustrates transapical delivery of a delivery system 1202through the apex of the heart into the left atrium LA via the leftventricle LV. The delivery system 1202 may be advanced over a guidewireGW into the left atrium, and a tissue penetrating tip 1204 helps thedelivery system pass through the apex of the heart by dilating thetissue and forming a larger channel for the remainder of the deliverysystem to pass through. The delivery catheter carries prosthetic cardiacvalve 1208. Once the distal portion of the delivery system has beenadvanced into the left atrium, the outer sheath 1206 may be retractedproximally (e.g. toward the operator) thereby removing the constraintfrom the atrial portion of the prosthetic valve 1208. This allows theatrial skirt 1210 to self-expand radially outward. In FIG. 12C, as theouter sheath is further retracted, the atrial skirt continues toself-expand and peek out, until it fully deploys as seen in FIG. 12D.The atrial skirt may have a cylindrical shape or it may be D-shaped asdiscussed above with a flat anterior portion and a cylindrical posteriorportion so as to avoid interfering with the aortic valve and otheraspects of the left ventricular outflow tract. The prosthesis may beoriented and properly positioned by rotating the prosthesis andvisualizing the alignment element previously described. Also, theprosthetic cardiac valve may be advanced upstream or downstream toproperly position the atrial skirt. In preferred embodiments, the atrialskirt forms a flange that rests against a superior surface of the mitralvalve and this anchors the prosthetic valve and prevents it fromunwanted movement downstream into the left ventricle.

As the outer sheath 1206 continues to be proximally retracted, theannular region of the prosthetic cardiac valve self-expands next intoengagement with the valve annulus. The annular region also preferablyhas the D-shaped geometry, although it may also be cylindrical or haveother geometries to match the native anatomy. In FIG. 12E, retraction ofsheath 1206 eventually allows both the anterior 1212 and posterior 1214tabs to partially self-expand outward preferably without engaging theanterior or posterior leaflets or the chordae tendineae. In thisembodiment, further retraction of the outer sheath 1206 then allows boththe anterior tabs 1212 (only one visible in this view) to complete theirself-expansion so that the anterior leaflet is captured between an innersurface of each of the anterior tabs and an outer surface of theventricular skirt 1216, as illustrated in FIG. 12F. The posterior tab1214 remains partially open, but has not completed its expansion yet.Additionally, the tips of the anterior tabs also anchor into the leftand right fibrous trigones of the mitral valve, as will be illustratedin greater detail below.

In FIG. 12G, further retraction of the outer sheath 1206 then releasesthe constraints from the posterior tab 1214 allowing it to complete itsself-expansion, thereby capturing the posterior leaflet PL between aninner surface of the posterior tab 1214 and an outer surface of theventricular skirt 1218. In FIG. 12H, the sheath is retracted furtherreleasing the ventricular skirt 1220 and allowing the ventricular skirt1220 to radially expand outward, further capturing the anterior andposterior leaflets between the outer surface of the ventricular skirtand their respective anterior or posterior tabs. Expansion of theventricular skirt also pushes the anterior and posterior leafletsoutward, thereby ensuring that the native leaflets do not interfere withany portion of the prosthetic valve or the prosthetic valve leaflets.The prosthetic valve is now anchored in position above the mitral valve,along the annulus, to the valve leaflets, and below the mitral valve,thereby securing it in position.

Further actuation of the delivery device now retracts the outer sheath1206 and the bell catheter shaft 1222 so as to remove the constraintfrom the hub catheter 1224, as illustrated in FIG. 12I. This permits theprosthetic valve commissures 1226 to be released from the hub catheter,thus the commissures expand to their biased configuration. The deliverysystem 1202 and guidewire GW are then removed, leaving the prostheticvalve 1208 in position where it takes over for the native mitral valve,as seen in FIG. 12J.

FIGS. 12K and 12L highlight engagement of the anterior and posteriortabs with the respective anterior and posterior leaflets. In FIG. 12K,after anterior tabs 1212 have been fully expanded, they capture theanterior leaflet AL and adjacent chordae tendineae between an insidesurface of the anterior tab and an outer surface of the ventricularskirt 1220. Moreover, the tips 1228 of the anterior tabs 1212 areengaged with the fibrous trigones FT of the anterior side of the mitralvalve. The fibrous trigones are fibrous regions of the valve thus theanterior tabs further anchor the prosthetic valve into the native mitralvalve anatomy. One anterior tab anchors into the left fibrous trigone,and the other anterior tabs anchors into the right fibrous trigone. Thetrigones are on opposite sides of the anterior side of the leaflet. FIG.12L illustrates engagement of the posterior tab 1214 with the posteriorleaflet PL which is captured between an inner surface of the posteriortab and an outer surface of the ventricular skirt 1220. Additionally,adjacent chordae tendineae are also captured between the posterior taband ventricular skirt.

FIGS. 13A-13L illustrate another exemplary embodiment of a deliverymethod. This embodiment is similar to that previously described, withthe major difference being the order in which the prosthetic cardiacvalve self-expands into engagement with the mitral valve. Any deliverydevice or any prosthetic cardiac valve disclosed herein may be used,however in preferred embodiments, the embodiment of FIG. 7 is used.Varying the order may allow better positioning of the implant, easiercapturing of the valve leaflets, and better anchoring of the implant.This exemplary method also preferably uses a transapical route, althoughtransseptal may also be used.

FIG. 13A illustrates the basic anatomy of the left side of a patient'sheart including the left atrium LA and left ventricle LV. Pulmonaryveins PV return blood from the lungs to the left atrium and the blood isthen pumped from the left atrium into the left ventricle across themitral valve MV. The mitral valve includes an anterior leaflet AL on ananterior side A of the valve and a posterior leaflet PL on a posteriorside P of the valve. The leaflets are attached to chordae tendineae CTwhich are subsequently secured to the heart walls with papillary musclesPM. The blood is then pumped out of the left ventricle into the aorta AOwith the aortic valve AV preventing regurgitation.

FIG. 13B illustrates transapical delivery of a delivery system 1302through the apex of the heart into the left atrium LA via the leftventricle LV. The delivery system 1302 may be advanced over a guidewireGW into the left atrium, and a tissue penetrating tip 1304 helps thedelivery system pass through the apex of the heart by dilating thetissue and forming a larger channel for the remainder of the deliverysystem to pass through. The delivery catheter carries prosthetic cardiacvalve 1308. Once the distal portion of the delivery system has beenadvanced into the left atrium, the outer sheath 1306 may be retractedproximally (e.g. toward the operator) thereby removing the constraintfrom the atrial portion of the prosthetic valve 1308. This allows theatrial skirt 1310 to self-expand radially outward. In FIG. 13C, as theouter sheath is further retracted, the atrial skirt continues toself-expand and peek out, until it fully deploys as seen in FIG. 13D.The atrial skirt may have a cylindrical shape or it may be D-shaped asdiscussed above with a flat anterior portion and a cylindrical posteriorportion so as to avoid interfering with the aortic valve and otheraspects of the left ventricular outflow tract. The prosthesis may beoriented and properly positioned by rotating the prosthesis andvisualizing the alignment element previously described. Also, theprosthetic cardiac valve may be advanced upstream or downstream toproperly position the atrial skirt. In preferred embodiments, the atrialskirt forms a flange that rests against a superior surface of the mitralvalve and this anchors the prosthetic valve and prevents it fromunwanted movement downstream into the left ventricle.

As the outer sheath 1306 continues to be proximally retracted, theannular region of the prosthetic cardiac valve self-expands next intoengagement with the valve annulus. The annular region also preferablyhas the D-shaped geometry, although it may also be cylindrical or haveother geometries to match the native anatomy. In FIG. 13E, retraction ofsheath 1306 eventually allows both the anterior 1312 and posterior 1314tabs to partially self-expand outward preferably without engaging theanterior or posterior leaflets or the chordae tendineae. In thisembodiment, further retraction of the outer sheath 1306 then allows boththe anterior tabs 1312 (only one visible in this view) to complete theirself-expansion so that the anterior leaflet is captured between an innersurface of each of the anterior tabs and an outer surface of theventricular skirt 1316, as illustrated in FIG. 13F. The posterior tab1214 remains partially open, but has not completed its expansion yet.Additionally, the tips of the anterior tabs also anchor into the leftand right fibrous trigones of the mitral valve, as will be illustratedin greater detail below.

In FIG. 13G, further retraction of the outer sheath 1306 then releasesthe constraint from the ventricular skirt 1320 allowing the ventricularskirt to radially expand. This then further captures the anteriorleaflets AL between the anterior tab 1312 and the ventricular skirt1316. Expansion of the ventricular skirt also pushes the anterior andposterior leaflets outward, thereby ensuring that the native leaflets donot interfere with any portion of the prosthetic valve or the prostheticvalve leaflets. Further retraction of sheath 1306 as illustrated in FIG.13H releases the constraint from the posterior tab 1314 allowing it tocomplete its self-expansion, thereby capturing the posterior leaflet PLbetween an inner surface of the posterior tab 1314 and an outer surfaceof the ventricular skirt 1318. The prosthetic valve is now anchored inposition above the mitral valve, along the annulus, to the valveleaflets, and below the mitral valve, thereby securing it in position.

Further actuation of the delivery device now retracts the outer sheath1306 and the bell catheter shaft 1322 so as to remove the constraintfrom the hub catheter 1324, as illustrated in FIG. 13I. This permits theprosthetic valve commissures 1326 to be released from the hub catheter,thus the commissures expand to their biased configuration. The deliverysystem 1302 and guidewire GW are then removed, leaving the prostheticvalve 1308 in position where it takes over for the native mitral valve,as seen in FIG. 13J.

FIGS. 13K and 13L highlight engagement of the anterior and posteriortabs with the respective anterior and posterior leaflet. In FIG. 13K,after anterior tabs 1312 have been fully expanded, they capture theanterior leaflet AL and adjacent chordae tendineae between an insidesurface of the anterior tab and an outer surface of the ventricularskirt 1320. Moreover, the tips 1328 of the anterior tabs 1312 areengaged with the fibrous trigones FT of the anterior side of the mitralvalve. The fibrous trigones are fibrous regions of the valve thus theanterior tabs further anchor the prosthetic valve into the native mitralvalve anatomy. One anterior tab anchors into the left fibrous trigone,and the other anterior tabs anchors into the right fibrous trigone. Thetrigones are on opposite sides of the anterior side of the leaflet. FIG.13L illustrates engagement of the posterior tab 1314 with the posteriorleaflet PL which is captured between an inner surface of the posteriortab and an outer surface of the ventricular skirt 1320. Additionally,adjacent chordae tendineae are also captured between the posterior taband ventricular skirt.

Tab Covering. In the exemplary embodiments described above, the tabs(anterior trigonal tabs and posterior ventricular tab) are generallynarrow and somewhat pointy. The embodiment previously described withrespect to FIG. 8 includes a horizontal strut on the posterior tab thathelps distribute force across a greater area and thereby reduces traumato the tissue. FIGS. 14A-14D illustrate another embodiment that ispreferably used with the anterior trigonal tabs to help reduce trauma.It may also be used with the posterior tab if desired.

FIG. 14A illustrates an anterior trigonal tab 1402 having a tip 1404.This tip can be narrow and pointy and thereby induce tissue trauma whendeployed into the tissue. Therefore, in some embodiments, it may bedesirable to place a cover over the tip to help reduce tissue trauma.FIG. 14B illustrates a polymer tab 1406 that may be attached to thetrigonal tab 1402. In other embodiments, the tab may be formed fromother materials such as fabric, metals, or other materials known in theart. The polymer tab may be laser cut from a sheet of polymer andincludes a long axial portion 1408 and an enlarged head region 1410. Aplurality of suture holes 1412 may be pre-cut into the polymer tab 1406and the holes are sized to receive suture material. Precut holes on thepolymer tab may be aligned with pre-cut holes on the trigonal tab andthen the polymer tab may be secured to the trigonal tab with sutures,adhesives, or other coupling techniques known in the art. A fabric cover1414 having two symmetric halves separated by a hinged area 1416 is thenwrapped around the polymer tab and attached to the polymer tab bysutures, thereby forming a shroud around the trigonal tab. The fabricmay be Dacron, ePTFE, or any other biocompatible material known in theart. Thus, the cover increases the surface area of contact between thetrigonal tabs and the tissue thereby reducing potential trauma andlikelihood of piercing the heart wall. Additionally, the material mayallow tissue ingrowth which further helps to anchor the prosthesis.Materials and dimensions are also selected in order to maintain the lowprofile of the device during delivery in the collapsed configuration.

While preferred embodiments of the present invention have been shown anddescribed herein, it will be obvious to those skilled in the art thatsuch embodiments are provided by way of example only. Numerousvariations, changes, and substitutions will now occur to those skilledin the art without departing from the invention. It should be understoodthat various alternatives to the embodiments of the invention describedherein may be employed in practicing the invention. It is intended thatthe following claims define the scope of the invention and that methodsand structures within the scope of these claims and their equivalents becovered thereby.

What is claimed is:
 1. A method of delivering an implantable prostheticvalve to a patient's heart, the patient's heart having a mitral valvewith an anterior leaflet and a posterior leaflet, said methodcomprising: providing a prosthetic valve, wherein the prosthetic valvecomprises an expandable frame having a first end, a second end oppositethe first end, a first anterior tab on an anterior portion of theexpandable frame, a posterior tab on a posterior portion of theexpandable frame, and a ventricular skirt adjacent the first end of theexpandable frame, and wherein the prosthetic valve has an expandedconfiguration for engaging the heart and a collapsed configuration;delivering the prosthetic valve in the collapsed configuration to thepatient's heart adjacent the mitral valve; expanding the first anteriortab radially outward such that a tip portion of the first anterior tabengages a first fibrous trigone on a first side of the anterior leafletof the mitral valve, and wherein the anterior leaflet and adjacentanterior chordae tendineae are disposed between the first anterior taband an outer anterior surface of the ventricular skirt; after radiallyexpanding the first anterior tab, radially expanding the posterior taboutward such that the posterior leaflet of the mitral valve and adjacentposterior chordae tendinae are disposed between the posterior tab and anouter posterior surface of the ventricular skirt; after radiallyexpanding the posterior tab, radially expanding the ventricular skirtoutward thereby engaging the anterior and posterior leaflets, whereinthe anterior leaflet and the adjacent anterior chordae tendinae arecaptured between the first anterior tab and the outer anterior surfaceof the ventricular skirt, and wherein the posterior leaflet and theadjacent posterior chordae tendinae are captured between the posteriortab and the posterior outer surface of the ventricular skirt.
 2. Themethod of claim 1, further comprising providing a delivery catheter,wherein the prosthetic valve is releasably coupled thereto.
 3. Themethod of claim 1, wherein delivering the prosthetic valve comprisestransapically delivering the prosthetic valve from a region outside theheart to the left ventricle of the heart.
 4. The method of claim 1,wherein delivering the prosthetic valve comprises transseptallydelivering the prosthetic valve from the right atrium to the left atriumof the heart.
 5. The method of claim 1, wherein delivering theprosthetic valve comprises positioning the prosthetic valve across themitral valve so that the first end of the expandable frame is inferiorto a portion of the mitral valve and the second end of the expandableframe is superior to a portion of the mitral valve.
 6. The method ofclaim 1, wherein expanding the first anterior tab comprises retracting aconstraining sheath from the first anterior tab so that the firstanterior tab is free to self-expand radially outward.
 7. The method ofclaim 1, wherein the prosthetic valve further comprises a secondanterior tab on the anterior portion of the expandable frame, the methodfurther comprising expanding the second anterior tab radially outwardsuch that a tip portion of the second anterior tab engages a secondfibrous trigone on a second side of the anterior leaflet opposite thefirst side of the anterior leaflet, and wherein the anterior leaflet andadjacent anterior chordae tendineae are disposed between the secondanterior tab and the outer anterior surface of the ventricular skirt. 8.The method of claim 7, wherein the second anterior tab expands radiallyoutward concurrently with expansion of the first anterior tab.
 9. Themethod of claim 7, wherein prior to engaging the first fibrous trigoneor the second fibrous trigone with the respective first or secondanterior tab, and prior to disposing the anterior leaflet and theadjacent chordae tendineae between the first or second anterior tab andthe outer anterior surface of the ventricular skirt, the methodcomprises partially expanding the first or the second anterior tabradially outward such that the first or the second anterior tab istransverse to a longitudinal axis of the prosthetic valve.
 10. Themethod of claim 7, wherein expanding the second anterior tab comprisesretracting a constraining sheath from the second anterior tab so thatthe second anterior tab is free to self-expand radially outward.
 11. Themethod of claim 1, wherein prior to disposing the posterior leaflet ofthe mitral valve and the adjacent posterior chordae tendineae betweenthe posterior tab and the outer posterior surface of the ventricularskirt, the method comprises partially expanding the posterior tabradially outward such that the posterior tab is transverse to alongitudinal axis of the prosthetic valve.
 12. The method of claim 1,wherein after the anterior leaflet and the adjacent anterior chordaetendineae are disposed between the first anterior tab and the outeranterior surface of the ventricular skirt, the method comprisespartially expanding the posterior tab radially outward such that theposterior tab is transverse to a longitudinal axis of the prostheticvalve, and wherein the posterior tab is partially expanded withoutdisposing the posterior leaflet of the mitral valve and the adjacentposterior chordae tendinae between the posterior tab and the outerposterior surface of the ventricular skirt.
 13. The method of claim 1,wherein radially expanding the ventricular skirt comprises retracting aconstraining sheath from the ventricular skirt so that the ventricularskirt is free to self-expand radially outward.
 14. The method of claim1, wherein the ventricular skirt comprises a plurality of barbs, andwherein expanding the ventricular skirt comprises anchoring theplurality of barbs into heart tissue.
 15. The method of claim 1, whereinthe prosthetic valve further comprises a plurality of commissures, andwherein expanding the ventricular skirt displaces the anterior andposterior mitral valve leaflets radially outward thereby preventinginterference between the commissures and both of the anterior andposterior leaflets.
 16. The method of claim 1, wherein expanding theventricular skirt displaces the anterior and posterior valve leafletsradially outward without contacting an inner wall of the left ventricle,and without obstructing a left ventricular outflow tract.
 17. The methodof claim 1, wherein radially expanding the ventricular skirt expands theventricular skirt asymmetrically such that an anterior portion of theventricular skirt is substantially flat, and a posterior portion of theventricular skirt is cylindrically shaped.
 18. The method of claim 1,further comprising reducing or eliminating mitral regurgitation.
 19. Themethod of claim 1, wherein the prosthetic valve carries a therapeuticagent, and the method further comprises eluting the therapeutic agentfrom the prosthetic valve into adjacent tissue.
 20. The method of claim1, wherein the prosthetic valve comprises an alignment element, andwherein a second fibrous trigone is disposed on a second side of theanterior leaflet opposite the first side of the anterior leaflet, themethod further comprising aligning the alignment element with an aorticroot and disposing the alignment element between the first and secondfibrous trigones.
 21. The method of claim 20, wherein aligning thealignment element comprises rotating the prosthetic valve.
 22. Themethod of claim 1, wherein the prosthetic valve further comprises aplurality of commissures with a covering disposed thereover whereby aplurality of prosthetic valve leaflets are formed, the method furthercomprising releasing the plurality of prosthetic valve leaflets from adelivery catheter.
 23. The method of claim 22, wherein the plurality ofprosthetic valve leaflets form a tricuspid valve, the tricuspid valvehaving an open configuration and a closed configuration, wherein theplurality of prosthetic valve leaflets are disposed away from oneanother in the open configuration thereby permitting antegrade bloodflow therethrough, and wherein the plurality of prosthetic valveleaflets engage one another in the closed configuration therebysubstantially preventing retrograde blood flow therethrough.
 24. Themethod of claim 1, wherein the prosthetic valve further comprises anatrial skirt, the method further comprising: expanding the atrial skirtradially outward so as to lie over a superior surface of the mitralvalve; and engaging the atrial skirt against the superior surface of themitral valve.
 25. The method of claim 24, wherein expanding the atrialskirt comprises retracting a constraining sheath from the atrial skirtso that the atrial skirt is free to self-expand radially outward. 26.The method of claim 24, further comprising moving the prosthetic valveupstream or downstream relative to the mitral valve to ensure that theatrial skirt engages the superior surface of the mitral valve.
 27. Themethod of claim 24, wherein engaging the atrial skirt against thesuperior surface seals the atrial skirt against the superior surface ofthe mitral valve to prevent or substantially prevent blood flowtherebetween.
 28. The method of claim 1, wherein the prosthetic valvefurther comprises an annular region, the method further comprising:expanding the annular region radially outward so as to conform with anannulus of the mitral valve; and engaging the annular region with themitral valve annulus.
 29. The method of claim 28, wherein expanding theannular region comprises retracting a constraining sheath from theannular region so that the annular region is free to self-expandradially outward.
 30. The method of claim 28, wherein expanding theannular region comprises asymmetrically expanding the annular regionsuch that an anterior portion of the annular region is substantiallyflat, and a posterior portion of the annular region is cylindricallyshaped.